Most wood workers distrust radial arm saws when rip-cutting. Radial arm saws are prone to kicking-back the work piece when rip-cutting unless it can be kept under firm control. Keeping such firm control can become quite hazardous as the work piece becomes narrow, and especially when the work piece becomes shorter. The operator is at risk using these smaller work pieces as his hands necessarily must work nearer to the saw blade in a cramped area with restricted visibility. These concerns are intensified when working with course grain hardwood such as oak. In fact, one radial arm saw currently sold has a warning against performing less than half-inch wide cuts.
Prior devices such as RIPSTRATE.RTM. or SHOPHELPER.RTM. attempt to overcome these short comings. However, neither is satisfactory as each is attached to the guide fence, limits the minimum cut width or is remote from the critical cutting area. Other devices are available which utilize spring fingers positioned before and after the blade. These devices have metallic components adjacent to the saw blade which presents an additional hazard if they become lose and strike the rotating saw blade. In addition, these devices are ineffective in the outrip position, especially if the setting is wide. Accordingly, there does not exist a device which holds down a work piece in the critical area where the saw is actually cutting. This is especially important if the work piece is very short and the cut-width is narrow.
All radial arm saws are equipped with pointed pivotal pawls on the exit side of the saw blade which must be adjusted to the thickness of the work piece being sawed. Their function is to restrain the work piece if it beings to travel in the wrong direction (i.e., back towards the operator). The pawls are usually four to six inches behind the cutting area of the saw blade, and are of little value when rip-cutting short pieces. Also, adjusting the pawls is an additional step after adjusting the saw blade, and is easy to forget.
In addition, a cross-cut is occasionally required when rip-cutting. Each prior art device must be removed or repositioned to allow adjustment from rip-cutting to cross-cutting. To return to rip-cutting, each prior art device must then be reinstalled or repositioned. It would be beneficial to provide a hold down device that does not significantly hinder adjustment from rip-cutting to cross-cutting.
The device of U.S. Pat. No. 4,532,841 refers to the front lip of a saw blade guard to a radial arm saw as being a work piece hold down. However, as soon as the end of the work piece passes this lip, it can no longer perform the hold down function. The danger of kick-back is greatest near the end of the cut. Therefore, the '841 patent does not provide hold down function at the most critical point of the rip-cutting operation.
The prior art hold down devices consist of cogged wheels, springs, clamps, rods and adjusting hardware. They are expensive and time consuming to install, and thus generally unacceptable to the average wood worker.
Therefore, the present invention provides a holdown shoe which holds a work piece firmly against the saw table immediately adjacent the saw blade during a rip-cut, and which does not hinder adjustment of the radial arm saw from the rip-cutting position to the cross-cutting position. In addition, the present invention is simple and inexpensive, compatible with all designs of saw guards currently available, can be retro-fitted to older saws, and provides a radial arm saw with the ability to make very small (i.e., less than a quarter inch) rip-cuts.